Data ONTAP 8.1 Cluster-Mode extends the storage domain of a high-availability (HA) pair of controllers to multiple pairs of controllers. With Data ONTAP 8.1 Cluster-Mode, capacity scales from terabytes to tens of petabytes, all transparent to your running applications. Your storage is virtualized across as many as 24 nodes, managed as a single logical pool of resources and name space. Virtualizing your storage across multiple pairs of controllers provides nearly limitless scalability for even the most data-intensive environments, regardless of network protocol, SAN or NAS. Data ONTAP 8.1 offers the first massively scalable unified storage platform with support for FC, iSCSI, FCoE, NFS and CIFS.

Configuration Bill of Materials

Item No

Qty

Type

Vendor

Model/Name

Description

1

24

Storage Controller

NetApp

FAS6240

FAS6240 with SAS CTRL and IO Expander

2

24

4-port SAS IO card

NetApp

IO Board SAS 4-port X2067-R6

4-port SAS IO Card

3

72

Disk Shelves with SAS Disk Drives

NetApp

DS4243-1511-24S-R5-C

DS4243 disk shelf with 24x450GB, 15K , SAS HDD

4

24

Flash Cache Module

NetApp

PAMII-512-R5

Flash Cache Module 512GB

5

1

Software license

NetApp

SW-6240-Cluster License

Data ONTAP 8.1 Cluster mode License

6

1

Software License

NetApp

SW-6240-NFS

NFS Software license SW-6240-NFS

7

2

Network Switch

Cisco

Cisco Nexus 5020

Cisco Nexus 5020 switches

Server Software

OS Name and Version

Data ONTAP 8.1 Cluster-Mode

Other Software

None

Filesystem Software

Data ONTAP 8.1 Cluster-Mode

Server Tuning

Name

Value

Description

vol modify <volume_name> -atime-update

false

Disable access time updates (applied to all volumes)

Server Tuning Notes

N/A

Disks and Filesystems

Description

Number of Disks

Usable Size

450GB SAS 15K RPM Disk Drives

1728

574.0 TB

Total

1728

574.0 TB

Number of Filesystems

single namespace

Total Exported Capacity

288 TB

Filesystem Type

WAFL

Filesystem Creation Options

The file-system was created using default values. An export policy was created giving full-access and applied to the file system.

Filesystem Config

96 RAID-DP (Double Parity) groups of 17 disks each were created across all the disks.

Fileset Size

176176.0 GB

The storage configuration consisted of 24 nodes connected in 12 SFO (storage failover) pairs forming a single cluster. Each node was connected to its own and partner's disks. A single disk pool or "aggregate" was created on each node comprised of 4 RAID-DP raid groups, each composed of 15 data disks and 2 parity disks which held the data for the file-system. A separate aggregate consisting of 3 disks in a single RAID-DP group was created to hold the Data ONTAP operating system files. Each node was allocated a spare disk. A single virtual server or "vserver" was created on the cluster, spanning all physical nodes. A flexible volume was then created on the data aggregate of each node in the cluster. Each volume was junctioned at the root of the single namespace of the vserver. Each volume was striped across all the disks in the data aggregate.

Network Configuration

Item No

Network Type

Number of Ports Used

Notes

1

Jumbo frame 10 Gigabit Ethernet

72

48 ports (2 per node) were used for the cluster network and 24 ports (1 per node) were used for the data network

Network Configuration Notes

The two cluster ports from each node were connected to a pair of Cisco Nexus 5020 switches, one port to each switch to provision the cluster network. This provides high availability for the cluster network in case of port or link failure. One port from each node and each load generator was connected to a Cisco Nexus 5596 switch for the data network. The data and cluster networks were on separate subnets. All the ports (cluster and data) were configured to use jumbo frames.

Benchmark Network

Each load generator was connected to the data network switch via a single 10GbE port. MTU size of 9000 was set for all connections to the switch.

Processing Elements

Processing Element Notes

Each storage controller has two physical processors and each physical processor is made up of four cores.

Memory

Description

Size in GB

Number of Instances

Total GB

Nonvolatile

Storage Controller Main Memory

48

24

1152

V

NVRAM Non-volatile Memory on PCIe adapter

4

24

96

NV

Flash Cache Module memory

512

24

12288

V

Grand Total Memory Gigabytes

13536

Memory Notes

Each storage controller has main memory that is used for the operating system and caching filesystem data. The FlashCache module is a read cache used for caching filesystem data. A separate, integrated battery-backed RAM module is used to provide stable storage for writes that may not have been written to disk.

Stable Storage

The WAFL filesystem logs writes and other filesystem data modifying transactions to the NVRAM adapter. In a storage-failover configuration, as in the system under test, such transactions are also logged to the NVRAM on the partner storage controller so that, in the event of a storage controller failure, any transactions on the failed controller can be completed by the partner controller. Filesystem modifying CIFS/NFS operations are not acknowledged until after the storage system has confirmed that the related data are stored in NVRAM adapters of both storage controllers (when both controllers are active). The battery-backed NVRAM ensures that any uncommitted transactions are preserved for at least 72 hours. In addition, de-staging to Flash on NVRAM preserves these transactions permanently.

System Under Test Configuration Notes

The system under test consisted of 24 FAS6240 storage controllers and 72 storage shelves, each with 24 450GB SAS disk drives. The controllers were running Data ONTAP 8.1 software operating in Cluster-Mode. The 24 storage controllers(nodes) were configured in a storage failover (SFO) configuration and connected to their respective disk shelves in a multi-path high-availability (MPHA) configuration. The SFO was provided by the storage failover software option in conjunction with an InfiniBand interconnect provided on the NVRAM adapter. Each node has physical resources that can be shared across the cluster providing a single namespace. The cluster network (N1) is comprised of 2 Cisco Nexus 5020 switches to provide redundancy. All the nodes in the cluster are connected through the cluster network and all the data throughout the cluster is accessible from any node. The data network (N2) is comprised of a Cisco Nexus 5596 switch. Each node and load-generator have a single 10GbE port connected to this switch. The data and cluster networks are on separate subnets. All ports and interfaces on the data and cluster networks have Jumbo frames enabled.

Testbed Configuration

Load Generator Configuration Notes

All clients accessed all mount points. Mount points were assigned to each client in a uniform manner making sure the load is evenly distributed across all clients and all interfaces.

Uniform Access Rule Compliance

For UAR compliance, each flexible volume was mapped to a subdirectory of the global namespace under root (/data1,/data2,...,/data24). Each volume was accessed over all data network interfaces (ip addresses ip1...ip24) such that each volume had a unique mount point on each node. This ensured that 1/24th of the total access on each node was done through a local interface and 23/24th of the total access was done through interfaces which were remote to the node the volume resides on. For these remote accesses, data traversed the cluster network. There were a total of 24 IP addresses available for data access, one per node. Each client mounted all 24 volumes using 10 different target IP addresses for a total of 240 mount points. The ten IP addresses selected per client for mounting each volume was done in a round-robin manner from the list of 24 IP addresses such that each successive client used the next ten IP addresses in the series. For example LG1 was assigned the following mount-point list: ip1:/data1, ip2:/data1,...,ip10:/data1,ip1:/data2,...,ip10:/data2,...,ip1:/data24,...,ip10:/data24. LG2 was assigned the following mount-point list picking up next IP adress in the list for each volume:ip11:/data1,ip12:/data1,...,ip20:/data1,...,ip11:/data24,...,ip20:/data24. LG3 continued from the next IP address circling back to the start of the series once the last IP was reached: ip21:/data1,..,ip24:/data1,ip1:/data1,..,ip6:/data1,...,ip21:/data24,..,ip24:/data24,ip1:/data24,..,ip6:/data24. This was done for all 36 clients. This ensured that data access to every volume was uniformly distributed across all clients and target IP addresses. The volumes were striped evenly across all the disks in the aggregate using all the SAS adapters connected to storage backend.

Other Notes

Other test notes: None.

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